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feat: new sample - Tables: Add empty column (#85)
* feat: new sample - Tables: Add empty column

* format code

* update base on comments

* update base on comments
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stephaniewang526 committed Jan 8, 2020
1 parent 7a83dab commit b8e4c1845c43b96b40cbebb0016c987919f781fe
Showing with 138 additions and 0 deletions.
  1. +71 −0 samples/src/main/java/com/example/bigquery/AddEmptyColumn.java
  2. +67 −0 samples/src/test/java/com/example/bigquery/AddEmptyColumnIT.java
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/*
* Copyright 2020 Google LLC
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

package com.example.bigquery;

// [START bigquery_add_empty_column]
import com.google.cloud.bigquery.BigQuery;
import com.google.cloud.bigquery.BigQueryException;
import com.google.cloud.bigquery.BigQueryOptions;
import com.google.cloud.bigquery.Field;
import com.google.cloud.bigquery.FieldList;
import com.google.cloud.bigquery.LegacySQLTypeName;
import com.google.cloud.bigquery.Schema;
import com.google.cloud.bigquery.StandardTableDefinition;
import com.google.cloud.bigquery.Table;
import java.util.ArrayList;
import java.util.List;

public class AddEmptyColumn {

public static void runAddEmptyColumn() {
// TODO(developer): Replace these variables before running the sample.
String datasetName = "MY_DATASET_NAME";
String tableId = "MY_TABLE_NAME";
String newColumnName = "NEW_COLUMN_NAME";
addEmptyColumn(newColumnName, datasetName, tableId);
}

public static void addEmptyColumn(String newColumnName, String datasetName, String tableId) {
try {
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests.
BigQuery bigquery = BigQueryOptions.getDefaultInstance().getService();

Table table = bigquery.getTable(datasetName, tableId);
Schema schema = table.getDefinition().getSchema();
FieldList fields = schema.getFields();

// Create the new field/column
Field newField = Field.of(newColumnName, LegacySQLTypeName.STRING);

// Create a new schema adding the current fields, plus the new one
List<Field> fieldList = new ArrayList<Field>();
fields.forEach(fieldList::add);
fieldList.add(newField);
Schema newSchema = Schema.of(fieldList);

// Update the table with the new schema
Table updatedTable =
table.toBuilder().setDefinition(StandardTableDefinition.of(newSchema)).build();
updatedTable.update();
System.out.println("Empty column successfully added to table");
} catch (BigQueryException e) {
System.out.println("Empty column was not added. \n" + e.toString());
}
}
}
// [END bigquery_add_empty_column]
@@ -0,0 +1,67 @@
/*
* Copyright 2020 Google LLC
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

package com.example.bigquery;

import static com.google.common.truth.Truth.assertThat;
import static junit.framework.TestCase.assertNotNull;

import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import java.util.UUID;
import org.junit.After;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;

public class AddEmptyColumnIT {
private ByteArrayOutputStream bout;
private PrintStream out;

private static final String BIGQUERY_DATASET_NAME = System.getenv("BIGQUERY_DATASET_NAME");
private static final String BIGQUERY_TEST_TABLE = System.getenv("BIGQUERY_TEST_TABLE");

private static void requireEnvVar(String varName) {
assertNotNull(
"Environment variable " + varName + " is required to perform these tests.",
System.getenv(varName));
}

@BeforeClass
public static void checkRequirements() {
requireEnvVar("BIGQUERY_DATASET_NAME");
requireEnvVar("BIGQUERY_TEST_TABLE");
}

@Before
public void setUp() throws Exception {
bout = new ByteArrayOutputStream();
out = new PrintStream(bout);
System.setOut(out);
}

@After
public void tearDown() {
System.setOut(null);
}

@Test
public void addEmptyColumn() {
String randomColumnName = "new_" + UUID.randomUUID().toString().replace('-', '_');
AddEmptyColumn.addEmptyColumn(randomColumnName, BIGQUERY_DATASET_NAME, BIGQUERY_TEST_TABLE);
assertThat(bout.toString()).contains("Empty column successfully added to table");
}
}

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